When using a Western-style toilet in a public restroom, it is requested that the toilet seat with which a user's skin comes into direct contact be kept clean and hygienic.
However, in a Western-style toilet installed in a public restroom, there rarely exists a toilet provided with special countermeasures for keeping the toilet seat clean and hygienic. In order to prevent one's skin from coming into direct contact with the toilet seat, a user generally places tissue papers or toilet papers cut into desired lengths on the toilet seat.
However, since the size of the cut toilet paper does not meet the standard of the toilet seat, it is difficult to stably arrange the toilet paper on the toilet seat, and therefore there are problems that a user often feels uneasy about shifting of the toilet paper on the toilet seat when using the toilet, and that it is extremely uneconomical because more than necessary amounts of toilet papers are tend to be cut to relive the concern that the user's skin may come into contact with the toilet seat.
Especially, a latest toilet seat is different from a conventional toilet seat that the entire surface of the toilet seat is relatively flat. That is, for the purpose of fitting to a users' body shape (specifically, the shape of a gluteal region when seated) to make the seated feeling better, many toilet seats employ a structure in which the toilet seat surface is slightly and downwardly inclined toward the inner peripheral edge portion from the outer peripheral edge portion. For this reason, when a tissue paper or a toilet paper is placed on the surface of the toilet seat, the placed paper moves from the outer peripheral edge portion toward the inner peripheral edge portion along the inclination of the toilet seat to slip down into the toilet bowl, causing a problem that a stable arrangement of the paper cannot be maintained.
Therefore, as shown in Patent Document 1, a toilet seat sheet is proposed in which an elliptical opening is formed in a center of a rectangular sheet made of a water-soluble paper. Such a toilet seat sheet will not slip down from the toilet seat, and therefore can be stably placed thereon. However, at the time of disposing the toilet seat sheet by flushing it in the toilet bowl after the use of toilet, a user had to remove the toilet seat sheet from the toilet seat to put it into the toilet bowl.
Therefore, as shown in Patent Document 2, a toilet seat sheet is proposed in which an elliptical hanging part is formed in a center of a rectangular sheet having a size capable of covering the entire toilet seat and the hanging part is connected to the sheet main body at the inner rear-side edge portion of the opening. In the toilet seat sheet, when the sheet main body is placed on the toilet seat, the hanging part hangs down toward the inner rear-side surface of the toilet bowl to form an opening for excretion. At this time, when the hanging part comes into contact with the inner rear-side surface of the toilet bowl, the hanging part is pulled in by the flow of the flushing water after the use of toilet, resulting in an automatic disposal of the toilet seat sheet from the toilet seat. However, since the inner rear-side surface of the toilet bowl is deep and steep in slope, the hanging part often did not come into contact with the inner rear-side surface of the toilet bowl. Therefore, in some cases, the hanging part was not pulled in by the flow of the flushing water after the use of toilet and the toilet seat sheet could not be automatically disposed from the toilet seat. Further, in the case of a toilet seat with a bidet function in which the gluteal region is automatically washed after the use of toilet, there also was a risk that the hanging part of the toilet seat sheet covers the nozzle of the toilet seat with a bidet function.
Under the circumstances, as shown in Patent Document 3, a toilet seat sheet is proposed in which a hanging part is formed in a center and the hanging part is connected to the sheet main body at the foremost end of the inner edge portion of the opening. In this case, since the inner front-side surface of the toilet bowl is shallow and the slope is gentle, the hanging part assuredly comes into contact with the inner front-side surface of the toilet bowl. Therefore, the hanging part can be pulled in by the flow of the flushed water after the use of toilet, so that the toilet seat sheet can be automatically disposed from the toilet seat.